For one example, see the treatment by the Saskatchewan Office of the Information and Privacy Commissioner. [*Financial and Consumer Affairs Authority of Saskatchewan (Re)*, 2014 CanLII 3995 (SK IPC)][1]: 

> With regards to such automatic email confidentiality notices, I considered these in Review Report F-2012-003 and found that depending on the wording and content, these confidentiality clauses could pass the ‘in confidence’ test.
>
> The disclaimer clause, at the end of several emails in the record before me, is worded similarly as the one I considered in the above Review Report. It is a more legalistic disclaimer than the usual confidentiality clause found at the end of general emails. 
>
> Therefore, I find that this would indicate that the communication was intended to be confidential and would meet the third part of the test for section 22(a) of FOIP.

However, my review of the case law is that these disclaimers are not generally determinative. Instead, they can be evidence of intention that a communication be in confidence. The weight of that evidence depends on the precise context and wording. And other evidence might pull in the other direction.

  [1]: https://canlii.ca/t/g2z6h